"What! What is this?"
"What is it?"
"Blood. Jill, you see if you can find anymore clues. I'll be examining this. I hope this isn't Chris' blood!"
"It'd be best if you, the master of unlocking, take it with you."
"You were almost a Jill sandwich!"
"It's a really powerful weapon, especially against living things!"
In summary people, I love Barry Burton and his snappy one liners. I can just imagine him busting out the science kit for that first quote when Jill encounters zombies #1, although I can also imagine he just poked it and thought "...yep, definitely blood". Also gotta love it when he walks over a dead, gigantic decomposing snake and ask Jills, "Find anything interesting?"